gpio: stm32: Remove .ofmatch callback

As compatible string "st,stm32-gpio" is no more used, .ofmatch
callback becomes useless, remove it.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/gpio/stm32_gpio.c b/drivers/gpio/stm32_gpio.c
index e89707c..302a434 100644
--- a/drivers/gpio/stm32_gpio.c
+++ b/drivers/gpio/stm32_gpio.c
@@ -210,15 +210,9 @@
 	return 0;
 }
 
-static const struct udevice_id stm32_gpio_ids[] = {
-	{ .compatible = "st,stm32-gpio" },
-	{ }
-};
-
 U_BOOT_DRIVER(gpio_stm32) = {
 	.name	= "gpio_stm32",
 	.id	= UCLASS_GPIO,
-	.of_match = stm32_gpio_ids,
 	.probe	= gpio_stm32_probe,
 #ifndef CONFIG_SPL_BUILD
 	.ops	= &gpio_stm32_ops,